【摘要】 采用自然放牧条件下的6、9、12、18月龄乌珠穆沁羊,取其半腱肌(Semitendinosus,ST)和背最长肌(Longissimus dorsi,LD),提取并分离纯化肌内结缔组织中的Ⅴ型胶原蛋白。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、傅里叶变换红外光谱(Fourier transform infrared spectroscopy,FTIR)、热变性温度和氨基酸组成分析,比较各月龄段肉羊不同部位中Ⅴ型胶原蛋白的特性。结果表明:Ⅴ型胶原蛋白主要由α1(Ⅴ)、α2(Ⅴ)、α3(Ⅴ) 3种亚基组成;ST和LD肌内结缔组织中Ⅴ型胶原蛋白的含量随着月龄的增长而增加,且各月龄间差异显著(P<0.05);在同一月龄段,ST肌内结缔组织中Ⅴ型胶原蛋白的含量高于LD;FTIR分析表明,各月龄段ST和LD肌内结缔组织中的Ⅴ型胶原蛋白均出现了主要吸收峰酰胺A、B及酰胺Ⅰ、Ⅱ、Ⅲ;ST肌内结缔组织中Ⅴ型胶原蛋白的热变性温度随着月龄的增长而显著升高(P<0.05),但9、12月龄间无显著差异(P>0.05);LD肌内结缔组织中Ⅴ型胶原蛋白的热变性温度随着月龄的增长而升高,但9、12月龄及12、18月龄间无显著差异(P>0.05),其他月龄均差异显著(P<0.05);氨基酸组成分析结果表明,Ⅴ型胶原蛋白的总氨基酸、亚氨基酸及羟脯氨酸含量随着月龄的增长而呈上升趋势,且各月龄间有显著差异(P<0.05)。本研究解释了随着肉羊月龄的增加,其骨骼肌肌内结缔组织中Ⅴ型胶原蛋白的特性变化。更多还原

【Abstract】 A comparative characterization of the type Ⅴ collagens extracted from the intramuscular connective tissues of Semitendinosus(ST) and Longissimus dorsi(LD) muscles in naturally grazed Ujimqin sheep aged 6, 9, 12 and 18 months was performed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE), Fourier transform infrared spectroscopy(FTIR), thermal denaturation temperature and amino acid composition analysis. The results showed that the type Ⅴ collagens consisted of three different subunits(α1(Ⅴ), α2(Ⅴ) and α3(Ⅴ)). For both muscles, the content of typeⅤ collagen was increased signi?cantly(P < 0.05) with age. At each age group, the content of type Ⅴ collagen in ST was higher than in LD. FTIR analysis showed the amide A, B, Ⅰ, Ⅱ and Ⅲ absorption bands of the type Ⅴ collagens in ST and LD muscles at each age group. The denaturation temperature of type V collagen in ST was signi?cantly increased with age(P < 0.05), although no significant difference(P > 0.05) was observed between 9-and 12-month-old sheep. The Td of type Ⅴ collagen in LD was increased with age(P > 0.05), except that there was no signi?cant difference between 9 and12 months and between 12 and 18 months of age. Amino acid analysis indicated that total amino acid content and imino acid contents(hydroxyproline and proline) were signi?cantly increased with age(P < 0.05). This study provides a theoretical foundation for explaining the effect of collagen on meat quality.更多还原